Piston water-meter



2 sheetssheen 1-.

Patented Dee. Z8

`LIIIIIIIUIMI .13. C. TERRY.

PIsToN. WATER-METER.

(No Model.)

2 sheets-sheetv 2.;

(No Model.)

E. C. TERRY. PISTONWATER METER..

vNo. 355,037. Patented Deo. 28, 1886.

f r I l l EDWARD C. TERRY, or HARTFORD, CONNECTICUT.

PISTON WATER-METER.

SPECIFICATION forming part or Letters Patent No. 355,037, dated December 28, 1886.

Applicatin tiled January 4, 1886. Serial No. 187,588. (No model.)

To aZZ whom it may concern:

Be it known that I, EDWARD C. TERRY, a. citizen of the United States, residing at Hart. ford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in -Water Meters, of which the following is a specification.

My invention relates to improvements in water-meters of the class known as pistonmeters, and the object of my invention is to prevent the pistons from hammering against the case. I

In the accompanying drawings, Figure 1 is a longitudinal section of my meter, partly in elevation. Fig. 2 is a transverse section, partly in elevation, of the same, less the side cap, the plane of section being indicated by the line ac x, Fig. 1. Fig. 3 is a longitudinal section of the case. Fig. 4 is a perspective view of one of the pistons, land Figs. 5 and 6 are diagrams of the two pistons and the va rions ports or valves on that side of the pistons which face the part of the case illustrated inA Fig. 3.

Adesignates the main body of the case, in which Iform two cylindrical piston-chambers, the ends of which are covered by caps B B. An openingis formed at one side ofthe case A for the introduction of a frame, E, within which the crank-shaft a is mounted. This opening is to be covered by a side cap, as indicated by broken lines in Fig. 2, and in this cap the registering mechanism may be placed. rlhe cranks b b of the shaft a engage suitable slots in the body of the respective pistons, and thereby determine their stroke.

D designates the threaded neck for connection with the inlet-pipe, and C a like neck for connection with the outlet-pipe. A passage leads from the inlet-pipe through one side of the case to the inlet-ports 1 and 2 in the piston-chambers, as indicated by broken lines in Fig. 3. Other passages through one side of the case connect the two piston-chambers and lead to the ports 3 and 4, 5 and 6, 7 and 8, and 9 and 10, respectively, all as indicated by broken lines in Fig. 3. Each piston has upon the side which faces these ports two depressions and three openings. The depressions are oblong, and serve to connect temporarily the ports of the case without letting water through the shell of the pistons while the openings let water through said shell, and, with the exception of openings 11 and 12, let the water into the body of the pistons, from whence it passes to the outlet. These openings and depressions, or valvesy as they are sometimes called, are designated in Figs. 5 and 6 by the figures 11 to 20, inclusive, the odd numbers being used here and in Fig. 3 for one side of the meter and the even numbers for the other side.

When the pistons are in certain positions,

ythe depression 15 connects the ports 1 and 5.

Depression 17 connects the ports 1 and 7. The opening 11 registers with the port 3, 13 with 5, and 19 with 7. The depression 16 connects the ports 2 and 4. Depression 18 connects the ports 2 and'lO. The opening 12 registers with/the port, 14 with 4L, and 2() with 10. rlhere are two piston-chambers, and when the pistons are placed therein there are four measuring-chambers, one at each end of each piston.

The major portion of my meter being old I consider it unnecessary,after thus pointing out the various passages and ports,' to explain in detail the iow of water through the machine' or the mode of operation of the entire machine, asit is substantially the same as others, except that I Cut ott the How of water from and to one end of cach piston in such manner as to stop the pistons before they strike the caps, or at least to prevent them from striking the caps with any considerable. force.- I accomplish this result by forming the openings 11 and 12 through the shell ot' the pistons, leaving a solid portion oneach side of said openings, which portions act alternately to open and close the ports 3 and 6; and I also form a passage, 21 and 22, from these openings 11 and 12 to the extreme ends of the piston, as shown in Figs. 1 and 4. rllhese openi-ngshave the effect to divide the piston end, or that face of the piston which is opposed to and forms one wall of the measuring-chamber, a part of said face being at the literal or eXtreme end ofthe piston, and a part o'fit being at the end of the passage 21 or 22. By this construction the passages leading from one piston-chamber to the other and terminating in the ports 3 and 6 lOO lead to the operative-piston end when the piss, ssaoaf/ ton is near the end of its stroke, so that said passage opens into thenieasuring-chamber at the end of the piston, as shown in Fig. 1. When the opening 11 in the piston registers with the port 3 of one measuringchamber, the piston on the other side of the meterwill be in a position to have the depression 16 connect the ports 2 and 4, so that water will be admitted through the ports 3 and 11 and passage 21 to the end of the piston, and consequently will move that piston toward the other end ofthe piston-chamber. Just before the piston reaches that end the solid portion of the piston-shellby that side of the opening 11 which is nearest this end of said piston covers up the port 3 and cuts ofi' the supply of water, and consequently the piston will stop without thumping the cap. l Upon the return of this piston the opening 14 of the opposite piston (which opening leads to the outlet) registers with the port4, so that water may ilow out through the opening 11 and port 3 and empty the measuring-chamber at that end of the pistonchamber as the piston returns Just before the piston completes its stroke the solid part of the piston-shell on the other side of this opening 11'(the side which is farthest v from this end of said piston) covers the port 3, so as to cut off the exit of water from that end of the pistonchainber, and consequently the piston will stop without thumping. The opening 12 of the other piston operates in like manner in connection with the ports 6, 5, and 1, depression 15, and opening 13. The solid portion of each pistonshell, in connection with the ports 3 and 6, acts as a valve to cover and uncover said ports, and for convenience I will designate the portions of the pistons which so act as the cut-off valve.

The water is admitted to and from the opposite ends of the pistons by ports 7, 8, 9, 10, 1, and 2, depressions 17 and 418, and openings 19 and 20;. but the ports 8 and 9 are never closed by the action of the pistons. Thisis substantially the ordinary construction. While it is necessary to employ only one cutoff valve in each piston when that valve operates to both cutoff the supply and discharge from and to one end of each piston-chamber, the same result may be attained by providing each piston with two cut-off valves, each acting one way only-that is, both valves acting to cut off the discharge from both ends of its own piston-chamber, or to cut oil' the supply to both ends of its own piston-ehamber, and a piston having two such valves acting to cut oii the water in its own piston-chamber I consider the full equivalent of a single cut-offact ing in a double capacity, as before stated.

By reference to Fig. 3 it will beseen that the ports of two measuringchambers-viz., the ports 3 and 6---are located within that portion of the cylindrical walls which is traversed by the respective pistons, while the ports of the other two measuring-ehambers-viz.,the ports 8 and 9-are located outside of that portion of the cylindrical walls which is traversed by the pistons, the former embodying my improvea ment and the latter being old. If that portion of the piston-shell which is between the ports 11 and 12 and the end of the piston nearest thereto were removed, then the piston-shell would cover the ports 3 and 6 when moving one way only, and consequently the piston# shell would act only to eut off the flow of water from the measuring-chamber at that end of the piston, and this is what is meant by a cut-off valve acting one way only. ports of all the measuring-chambers would have to be located within that portion of the cylindrical wall which is traversed by the piston; but by the specific construction shown it is only necessary to locate the ports of two of the measuring-chambers in the p ath traversed by the piston. In order to determine the stroke of the pistons and make the meter an operativecone,the shaft and cranks,or some equiva` lent mechanism, must be employed. While I have described the piston-shell as covering the' ports 3 and 6, it does not close them absolutely water-tight, but substantially covers them, so as to practically, but not absolutely, cut olf the supply and discharge and thereby prevent thumping. There should always be a very slight open-ing or leakage when the pis ton is at the end of its stroke, in order to start the piston on its return.

By my construction I prevent the thumping In such a case the or hammering of the pistons, and I am therefore enabled to run them much faster, and consequently make a smaller machine answer for a given size of pipe.

I claim as my invention- 1. In a pistonmeter, the combination of two pistons and the case having two independent piston-chambers, and a passage or passages leading from each chamber to a point in the other opposite the piston end when near the end of its stroke, said passages having a port at each end formed Wholly in the cylindrical wallsof said piston-chambers, the said pistons each having two portions which act alternately as valves to'open and close said ports, whereby each of said pistons acts to eut oft' the water at each end of yits own stroke, substantially as described, and for the purpose specified.

2. In a piston-meter, the combination of two pistons, ashaft and cranks for determining the stroke of said pistons, and the case having two' independent piston-chambers, and a passage or passages leading from each chamber to a point in the other opposite the piston end when near the end of its stroke, said passages having a port at each end formed wholly in the cylindrical Walls of said piston-chambers, the said pistons cach having two portions which act alternately as valves to open and close said'ports,whereby each of said pistons acts-to cut olf the water at each end of its own stroke, substantially as described, and for the purpose specified.-

EDWARD C. TERRY. Witnesses:

WM. W. SMITH, EDWARD BRownR.

IOO 

